1. Technical Field
The present invention relates to a correction method for NC data for high-accuracy machining.
2. Background Art
After move commands for servomotors for driving individual axes of a machine tool are given to a servo system in accordance with NC data, the servo system carries out servo processing, whereupon the servomotors for the individual axes are driven to execute machining. However, a delay in the servo system can be a hindrance in executing high-accuracy machining. The delay in the servo system causes an actual tool path to deviate from the paths of machining blocks commanded by the NC data, thereby causing machining errors.
In the ordinary machining, these machining errors resulting from the follow-up delay are within an allowable range and thus are negligible. In carrying out special high-accuracy machining, however, the machining errors resulting from the follow-up delay are not negligible. In order to reduce the machining errors caused by the follow-up delay, therefore, a conventionally adopted method is such that machining is carried out at a machining speed lowered to a degree that the machining errors resulting from the follow-up delay come within the allowable range.
Reduced machining speed, however, naturally results in longer machining time, and searching for an appropriate machining speed by trial and error takes much time. Thus, it is not easy to modify data in NC programs properly in order to execute high-accuracy and high-efficiency machining.